Reliable new immunosensor for atrazine pesticide analysis

The aim of the present research was to develop a highly selective and sensitive amperometric immunosensor for atrazine based on a "competition" assay procedure. An immunosensor device for the determination of triazinic pesticides based on two different competition procedures is therefore described. The immunosensor developed uses an amperometric electrode for hydrogen peroxide as transducer and the peroxidase enzyme as marker. The results demonstrate the full validity of this immunosensor method which was optimized by comparing two different "competition" operating procedures. The results obtained using the new immunosensor were then compared with those found using an inhibition OPEE (Organic Phase Enzyme Electrode) for triazinic pesticide detection, which showed no selectivity toward different classes of triazinic, carbamate or organophosphate pesticides. The immunosensor developed displayed on the contrary an appreciable selectivity both toward different classes of pesticides and toward triazinic or benzotriazinic products. In addition, the K(aff) value was evaluated. Lastly, the immunosensor was also used to test triazinic pesticide recovery from common real matrices such as milk and vegetal samples, obtaining good recoveries. (C) 2011 Elsevier B.V. All rights reserved.